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Redes De Ingeniería De Redes Cia Para Sectores Marginados De Bogotá Usando Redes Ad-Hoc Mesh

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Redes De Ingeniería De Redes Cia Para Sectores Marginados De Bogotá Usando Redes Ad-Hoc Mesh ANÁLISIS ACERCA DE LA IMPLEMENTACIÓN DE SISTEMAS DE VIDEO VIGILANCIA SOBRE REDES MESH AN ANALYSIS OF VIDEO SURVEILLANCE SYSTEMS IMPLE- MENTATION OVER MESH NETWORKS Christian C. Fuquene Ingeniero Electrónico, estudiante Abstract de Especialización en Tele- In recent years, Ad-hoc Mesh networks have attracted great informática de la Universidad Distrital Francisco José de Cal- military activities, rescue operations and time critical appli- das, de Bogotá, Colombia. cations. This article presents the implementation analysis of [email protected]. attention due to their potential use in various fields such as a video surveillance system that covers marginalized areas edu.co of Bogotá and uses Ad-hoc Mesh Networks. Internationally recognized protocols such as AODV, OLSR, BATMAN are des- Octavio J. Salcedo cribed and compared in order to select the most suitable. Ingeniero de Sistemas, MSc. en Teleinformática de la Universi- the Night-wing Firmware is selected from an extensive list of dad Distrital, MSc. en Economía, Similarly,hardware thecomponents. router with Finally, the best the costcost-benefit of implementing relation toa wi fit- se desempeña como docente de red phase and the cost of a wireless phase, both offering video planta de la Universidad Distrital surveillance services, are compared. “Francisco José de Caldas” [email protected] Keywords: Architecture, protocol, mesh network. John J. Triana Resumen Ingeniero de Sistemas, estudiante En los últimos años las redes Ad-hoc Mesh, han estado atra- de Especialización en Teleinfor- yendo la atención por su uso potencial en varios campos ta- mática de la Universidad Distrital les como las actividades militares, operaciones de rescate y Francisco José de Caldas, de Bo- aplicaciones en tiempo crítico. En este artículo se presenta el gotá, Colombia. análisis de la implementación de un sistema de video vigilan- [email protected] Redes de Ingeniería de Redes cia para sectores marginados de Bogotá usando redes Ad-hoc Mesh. Se describen los protocolos más usados internacional- mente AODV, OLSR, BATMAN y se comparan para seleccionar el más óptimo. De igual forma se selecciona de una extensa listade implementación de hardware el derouter un escenario con el mejor cableado costo beneficio contra un que esce se- adecuanario inalámbrico al firmware que nightwing. ofrecen Alsistemas final se derelacionan video vigilancia. los costos Palabras clave: Arquitectura, protocolo, redes Mesh. Tipo: Artículo de revisión Fecha de Recepción: Marzo 29 de 2010 Fecha de Aceptación: Mayo 14 de 2010 32 Vol. 1 │ No. 1 │ Pag. 32-42 │ Enero - Junio 2010 1. INTRODUCCIÓN (Wireless Local Area Network). En 1999 Redes de Ingeniería Las redes Mesh tienen su origen en las pri- meras redes ad-hoc. (Una red ad-hoc ina- ella tasaIEEE de aprueba transferencia la revisión hasta 802.11blos 11 Mbit/s. de la lámbrica es aquella en la que no hacen falta normaEse mismo original año 802.11,nace la la asociación cual aumentaba WECA nodos especiales que enrutan y gestionan (Wireless Ethernet Compatibility Alliance), - creada por Nokia y Symbol Technologies., cidad de reenviar paquetes dirigidos a otros elnodos tráfico, de sinola red). que Lascada primeras nodo tiene redes la capa ina- permitiese fomentar más fácilmente la tec- lámbricas ad-hoc fueron desarrolladas por cuyanología finalidad inalámbrica era creary asegurar una marca la compa que- DARPA (Agencia de Investigación de Pro- tibilidad de equipos. Esta asociación pasó yectos Avanzados de Defensa) en los años 70 y operaban en radiofrecuencias UHF y - se denominaban Packet Radio Networks. a denominarse Wi-Fi Alliance en 2003. De Las primeras redes fueron ALOHANET y esta forma, en abril de 2000 WECA certi PRNET. De allí surgen las comunidades de fica la interoperabilidad de equipos según la norma IEEE 802.11b, bajo la marca Wi- primeras redes, la más importante y aún en Figexpanden [2].Gracias a los a hogaresesta interoperabilidad mediante enruta las- radioaficionadosfuncionamiento AMPRNET, que implementaron implementa sus el implementacionesdores y AP (Acces Points) de la tecnología inalámbricos Wifi que se protocolo TCP/IP y tiene su propio rango permiten conectar diferentes dispositivos a de direcciones IP reservado. A continuación Internet sin necesidad de cables. Este auge las redes ad-hoc adquieren la capacidad de permite que el costo de los dispositivos ina- moverse y se crean las redes MANET (Mo- lámbricos sea cada vez menor y aparezcan bile Ad-hoc Network), promovidas nueva- las primeras comunidades de redes comu- mente por la investigación militar y DARPA. nitarias con desarrolladores y entusiastas En 1983 esta agencia inicia el proyecto SU- de software libre, que impulsarían nuevos - protocolos y tecnologías inalámbricas li- lidad era desarrollar una red ad-hoc móvil bres. Es en este contexto cuando surgen RANde bajo (Survivable coste y queRadio pudiese Network) implementar cuya fina comunidades, centros de investigación y protocolos Packet radio más complejos que docencia y empresas interesadas en desa- PRNET. En los años 90 se iniciaron distintos rrollar tecnologías inalámbricas en malla o proyectos en el ámbito militar y de defensa, redes Mesh, que poseen la particularidad como GloMo (Global Mobile) y NTDR (Near de utilizar la infraestructura de las redes Term Digital Radio). En 1997 el ejército de existentes y las redes ad-hoc, y que son ca- EE.UU. empezó el desarrolló del Tactical In- paces de extender y compartir conectividad ternet (TI), una red inalámbrica multisalto inalámbrica en lugares donde por razones (multi-hop) packet radio que conformase económicas las posibilidades son mínimas. un campo de batalla militar totalmente di- En la Fig. 1 se presentaun esquema básico gitalizado, en el que cada unidad tiene co- de las redes Mesh. municación bidireccional de datos con to- das las demás unidades [1]. Con la impresionante difusión de internet en los años 90 y la aparición de los dis- positivos móviles las redes inalámbricas empiezan a ser una alternativa a las redes - - cableadas, el IEEE en 1997 define la espe cificaciónuna red de IEEE área 802.11, local inalámbricaun estándar WLAN inter Fig. 1. Redes Mesh [3]. nacional que define las características de Análisis acerca de la implementación de sistemas de video vigilancia sobre redes MESH Christian C. Fuquene/Octavio J. Salcedo/ John J. Triana 33 La expectativa generada por las redes de implanto un sistema inalámbrico de video malla inalámbricas han disparado los avan- vigilancia con diseño en malla, el cual pro- ces en distintos niveles. En primer lugar, porciona una cobertura de vídeo de calidad los fabricantes están impulsando sus solu- HD para las tiendas, restaurantes y zonas ciones de redes inalámbricas con protoco- de aparcamiento de un importante centro los de malla propietarios, como Sky-Pilot, comercial. El diseño utilizo 13 cámaras de BelAiry SaxNet. En segundo lugar, las re- vídeo conectadas por 10 enrutadores ina- des comunitarias en malla han crecido y lámbricos en malla [7]. ofrecen conectividad y capacidad. El MIT Roofnet o el Freifunk en Berlín son claros En Alemania se encuentra el proyecto Frei- ejemplos que han crecido a un tamaño de funk, esta red experimental de comunidad - mentando. En tercer lugar, bancos de prue- nodos basado en OLSR Firmware Freifunk. hastabas de 200 investigación puntos de talesacceso como y siguen Magnets au urbanaA este software está conformada se le han dado por muchos unos usos200 Redes de Ingeniería y RescueMesh han desarrollado pruebas en proyectos comunitarios y de desarrollo experimentales de redes en malla y han [8]. La red inalámbrica CUWiN en Illinois, entendido sus limitaciones y capacidades. es una iniciativa de desarrollo e investi- En cuarto lugar, las actividades de norma- gación con una implemen-tación de códi- lización se han centrado en las redes en go abierto del protocolo de enrutamiento HSLS, apostando a una red Ad-Hoc inalám- brica escalable y altamente robusta [9]. En mallainalámbricas multisalto, de incluidaárea personal la 802.11s (WPAN) para la India existe una red comunitaria en Dha- redesy redes WLAN de sensores. y la IEEE Esfuerzos 802.15 para similares redes ramsala, la cualestá encargada de realizar están encaminados hacia el futuro de la la conexión devarios campus. Actualmente tecnología, tales como el estándar IEEE en Bogotá se encuentra en marcha un pro- - yecto denominado Bogotá-Mesh, el cual nexión (multipunto a multipunto) junto al busca la creación de una red abierta, des- 802.16,tradicional el cual punto incluye a multipunto un esquema (PMP). de co Al centralizada, comunitaria, independiente mismo tiempo se ha establecido un nuevo y autónoma que sirva como herramienta para difundir proyectos de carácter comu- - gruponacional, (IEEE este 802.16j) concepto el decual WMN se centra (Wireless en la especificaciónMesh network) multisalto[4]. o red inalámbrica A nivel en intermalla nitario,2. ARQUITECTURA social, cultural DEL y científico SISTEMA [10]. está muy difundido tanto en Europa como en Norte América. Son diversos los servi- 2.1 Protocolos cios que se están brindando a través de la Dado que se trata de una red de topología los siguientes párrafos se relacionan algu- implementaciónnos de los proyectos de este desarrollados tipo de red a[5]. nivel En se establecen entre dispositivos cambian mundial empleando las bondades ofrecidas dinámicadinámicamente, y auto configurable,con lo cual son las necesarios rutas que por las redes Mesh. una serie de protocolos para transmitir los datos con un bajo coste de transmisión, En la ciudad de Zaragoza en España, don- como por ejemplo, encontrar la ruta con de se brindan servicios de ToIP y VoIP, y en menos saltos. Oklahoma, Estados Unidos, se generó una red para el servicio público y servicios de - - colos de enrutamiento los divide en: chusetts, el Departamento de Policía de Ha- Una clasificación tradicional de los proto vigilanciaverhill selecciono en los patrulleros esta tecnología [5]. En para Massa su Reactivos, en los que un nodo sólo inter- cambia información de control cuando • sistema de vídeovigilancia [6].
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